The technology disclosed here relates to a connection ring for the removable attachment of a fuel supply unit on a motor vehicle tank opening.
Such connection rings, also called camlock rings, are known per se from the state of the art. European Patent Document EP 1 571 030 B1, for example, discloses a connection ring, which is also illustrated in FIGS. 1 and 2. The known connection ring 80 of FIG. 1 has a cap region 88, which is not shown in FIG. 2. The cap region 88 is fastened to the motor vehicle tank 20 by way of a flange region. The flange region is formed by an inner ring 82 and an outer ring 81 (compare FIG. 2).
A bayonet mechanism is used for the fastening. The bayonet mechanism comprises two movements: In a first movement, the connection ring 80 is placed onto the jaws 25 provided at the vehicle tank 20. The jaws 25 are introduced into wide introduction openings 83 of the flange region. During the placing of the connection ring 80, an outer edge 81a of the outer ring 81 takes over the positioning or guidance of the connection ring 80. During the placing of the connection ring 80, the outer edge 81a first comes in contact with the rounded edge 25a of the L-shaped jaw 25 and then slides along the rounded edge 25a and the shaft part of the jaw 25. Subsequently, in a second movement, the connection ring 80 is rotated in the circumferential direction U relative to the motor vehicle 20. As a result of the rotation, the fastening elevations 85 of the connection ring 80 slide under the jaws 25 until the fastening elevations 85 are held in the indentations provided in the jaws 25 (also compare FIGS. 6 and 7 of European Patent Document EP 1 571 030 B1). As a result of the rotation of the connection ring 80, the shaft part of the L-shaped jaws 25 arrives in the slot region 84, which is connected with the introduction region 83. FIG. 1 is a cross-sectional view in the rotated condition. In this rotated condition, the connection ring 80 presses the fuel supply unit 30 by way of the seal 40 onto the edge of the opening 21 of the motor vehicle tank 20.
Recesses 86 are provided at the outer ring 81. These recesses 86 are used as the contact surface for the mounting tool, by which the connection ring 80 is rotated. The mounting tool for rotating the connection ring 80 has several pins, which extend in the axial direction Z (compare FIG. 1), and engage behind the recesses 86. The engaging-behind prevents the tool from sliding off. Between the recess 86 and the fuel tank 20, an axial gap 5 (see FIG. 1) is provided for permitting the pins to engage behind the recesses 86.
A disadvantage of this known solution is the fact that the inner edge 82a of the inner ring 82 as well as the outer edge 81a of the outer ring 81 have to be provided with a sufficiently good production tolerance, so that, even when the installation space is comparatively small, the jaws 25 can be introduced and rotated without any problem. Furthermore, the connection ring requires a comparative large installation space. The size of the connection ring is significant especially also during the mounting/maintenance, because smaller connections rings are easier to mount. When evaluating the installation space, it should also be taken into account that the tool also still has to be applied from the outside. In addition to the installation space, the weight and the manufacturing costs are also significant.
It is an object of the technology disclosed here to reduce or eliminate the disadvantages of the known solutions. This/these task(s) is/are achieved by a connection ring according to embodiments of the invention.
The technology disclosed here thus relates to a connection ring. The connection ring is used for the removable attachment of a fuel supply unit to a motor vehicle tank opening of a motor vehicle tank, for example, a plastic fuel tank or a steel fuel tank.
The connection ring has a ring top side and a ring bottom side. In the mounted condition, the ring bottom side faces the motor vehicle tank opening. In the mounted condition, the ring top side will then face away from the motor vehicle tank opening.
The connection ring has at least one attachment elevation, which projects from the ring top side. In particular, the attachment elevation projects such that, by rotating the connection ring relative to the motor vehicle tank opening, the fuel supply unit can be attached to the motor vehicle tank. In the process, the bayonet mechanism known from the state of the art is used, which will be explained in detail in the following.
The connection ring includes at least one tool engagement region which is constructed such that a tool can contact the connection ring in the tool engagement region so a torque can be transmitted from the tool to the connection ring, in which case at least a section of the tool engagement region and a section of the attachment elevation are spaced at an equal distance from the center M of the connection ring in the radial direction R from the center M. In other words, the tool engagement region and the attachment elevation, viewed in the circumferential direction U of an imagined graduated circle T, are arranged behind one another and in an overlapping manner. In other words, again, the connection ring includes at least one graduated circle T around the center M, which simultaneously extends through the tool engagement region and through the attachment elevation.
As a result of this advantageous embodiment of the connection ring, it becomes possible to eliminate the previous recesses 86 (compare FIG. 2) which were provided comparatively far on the outside at the outer ring 82 (compare FIG. 2). On the whole, the connection ring can be constructed to be smaller and lighter. Furthermore, less space is required for the mounting.
The tool engagement region may be constructed as a recess. The recesses are preferably arranged in the circumferential direction U distributed over the circumference between the attachment elevations. The recesses may have recess edges which project from the ring top side in the axial direction Z, particularly such that a tool can engage behind the edges, for example, even if the connection ring is situated on a motor vehicle tank opening of a fuel tank. Instead of recesses, other suitable interlocking devices would also be possible, such as projections, edges, etc. provided on the ring top side.
The connection ring may have at least one guide, which is provided, at least in regions, on the outer edge of the connection ring. The guide is suitable for guiding a frontal edge of a jaw of a fuel tank in a positioning manner. For the positioning, the outer edge may have a chamfer or a curvature at or in the transition region to a ring bottom side. The connection ring is preferably produced of sheet metal. Furthermore, the connection ring may also be made of another material, for example, of a plastic material. The guide may further have a region projecting from the ring top side. The projecting region may, for example, be a bent sheet metal part.
According to the technology disclosed here, the positioning/guiding of the connection ring relative to the jaws is implemented by a guiding element on the connection ring. The outer ring 81 together with the outer positioning edge 81a can therefore be eliminated. This advantageously reduces the weight, the installation space and material and production expenditures. In addition, the smaller connection rings can be mounted more easily.
At least a section of the guide and a section of the tool engagement region and/or the attachment elevation can be spaced at an equal distance from the center M of the connection ring in the radial direction R from the center M. In other words, viewed in the circumferential direction U, also the guide can be arranged in an overlapping manner and have a common graduated circle T with the tool engagement region and/or the attachment elevation. Such an embodiment is particularly compact.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.